Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: results of a randomized placebo-controlled trial.

Abstract

BACKGROUND AND PURPOSE:

To determine the effect of B vitamin treatment on the incidence of cancer among patients with stroke or transient ischemic attack.

METHODS:

A total of 8164 patients with recent stroke or transient ischemic attack were randomly allocated to double-blind treatment with 1 tablet daily of placebo or B vitamins (2 mg folic acid, 25 mg vitamin B(6), 500 μg vitamin B(12)) and followed for a median of 3.4 years for any cancer as an adverse event.

RESULTS:

There was no significant difference in the incidence of any cancer among participants assigned B vitamins compared with placebo (4.04% versus 4.59%; risk ratio, 0.86; 95% CI, 0.70-1.07) and no difference in cancer mortality (2.35% versus 2.09%; risk ratio, 1.09; 0.81-1.46). Among 1899 patients with diabetes, the incidence of cancer was higher among participants assigned B vitamins compared with placebo (5.35% versus 3.28%; adjusted risk ratio, 2.21; 1.31-3.73), whereas among 6168 patients without diabetes, the incidence of cancer was lower among participants assigned B vitamins compared with placebo (3.66% versus 5.03%; adjusted risk ratio, 0.67; 0.51-0.87; P for interaction=0.0001).

CONCLUSIONS:

Daily administration of folic acid, vitamin B(6), and vitamin B(12) to 8164 patients with recent stroke or transient ischemic attack for a median of 3.4 years had no significant effect, compared with placebo, on cancer incidence or mortality. However, a post hoc subgroup analysis raises the hypothesis that folic acid treatment may increase the incidence of cancer among diabetics and reduce the incidence of cancer among nondiabetics with a history of stroke or transient ischemic attack.

• Authors: Graeme J Hankey, John W Eikelboom, Qilong Yi, Kennedy R Lees, Christopher Chen, Denis Xavier, Jose C Navarro, Udaya K Ranawaka, Wasim Uddin, Stefano Ricci, John Gommans, Reinhold Schmidt, VITAmins TO Prevent Stroke (VITATOPS) Trial Study Group
• Journal: Stroke (Stroke) Vol. 43 Issue 6 Pg. 1572-7 (Jun 2012) ISSN: 1524-4628 [Electronic] United States
• PMID: 22474057 (Publication Type: Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Vitamin B Complex

Topics

• Double-Blind Method
• Female
• Humans
• Ischemic Attack, Transient (complications, mortality)
• Male
• Neoplasms (mortality, prevention & control)
• Stroke (complications, mortality)
• Vitamin B Complex (administration & dosage)